Living on the edge: Conservation genetics of seven thermophilous plant species in a High Arctic archipelago

Abstract

Small and peripheral populations often contain low levels of genetic variation. This may limit their ability to adapt to environmental change, including climate warming. In a recent study published in AoB PLANTS, Birkeland, Skjetne and colleagues show that many rare and threatened plant species in the High Arctic archipelago Svalbard harbour low levels of genetic variation. Most of them are probably relicts from the early Holocene warmer period. They have likely experienced strong genetic founder/bottleneck effects due to climatic limitations. Even though temperatures now are rising, it is highly uncertain whether this will be beneficial for these warmth-demanding species.

The importance of marginal population hotspots of cold‐adapted species for research on climate change and conservation

“…A similar conclusion has been recently reached by Birkeland et al. () in a study that identified separate conservation units at the northern distribution boundary of some arctic species. This study demonstrates how the discovery of these refugia can alter our application of conservation efforts, in terms of legal protection, red listing (Abeli, Gentili, Rossi, Bedini, & Foggi, ) and translocation (Birkeland et al., ).…”

“…() in a study that identified separate conservation units at the northern distribution boundary of some arctic species. This study demonstrates how the discovery of these refugia can alter our application of conservation efforts, in terms of legal protection, red listing (Abeli, Gentili, Rossi, Bedini, & Foggi, ) and translocation (Birkeland et al., ). Finally, identifying marginal population hotspots will enrich our understanding of the causes of endemism.…”

“…In the Northern Hemisphere for example, northward expansion of plant species is usually limited by low temperatures and frost sensitivity, while southward range expansion is limited by a combination of temperature, water availability and competition (Boucher-Lalonde et al, 2012;Heegaard & Vandvik, 2004). Geographically and/or ecologically marginal populations are of interest in evolutionary biology because their genetic differentiation, phylogenetic history and evolutionary potential may promote speciation events or prevent extinction (Birkeland, Skjetne, Brysting, Elven, & Alsos, 2017;Hampe & Petit, 2005;Holliday, Suren, & Aitken, 2012;Kawecki, 2008). Their importance becomes especially pertinent in the context of ongoing global climatic changes.…”

A transcriptome for the early-branching fernBotrychium lunariaenables fine-grained resolution of population structure

“…Botrychium species show no meaningful genetic differentiation within populations (Farrar, 1998;Hauk and Haufler, 1999) or low genetic differentiation among populations (Camacho and Liston, 2001;Swartz and Brunsfeld, 2002;Birkeland et al, 2017). However, the absence of genetic differentiation reported by previous studies may well stem from low marker resolution.…”

“…Previous population genetic studies based on isozymes showed a lack of genetic differentiation among morphologically recognized types (Williams et al, 2016), and the low amount of genetic variation detected within Botrychium populations suggests pervasive self-fertilization (Farrar, 1998;Hauk and Haufler, 1999). Furthermore, genetic differentiation among populations and regions was found to be low suggesting that gene flow may occur (Camacho and Liston, 2001;Swartz and Brunsfeld, 2002;Birkeland et al, 2017). These studies highlight the need for powerful, genome-wide marker systems to resolve population structures, life histories and taxonomy of these early-branching ferns.…”